Transmission of electrical impulses.



. No. 758,598. PATENTED APR. 26, 1904.

J. s. RICHMOND. TRANSMISSION OF ELECTRICAL IMPULSES.

APPLICATION FILED EE PT. 18, 1903.

' no MODEL;

III"

UNITED STATES Patented. April 26, 1904.,

PATENT OFFICE.

JOHN STANLEY RICHMOND, OF NEW YORK N. Y.

TRANSMISSION OF ELECTRICAL IMPULSES.

SPECIFICATION forming part of Letters Patent No. 758,598, dated April26, 1904. Original application filed April 27, 1901, Serial No- 57,821.Divided and this application filed September 16, 1903. SerialITO-173,480.

To all whom, it may concern:

Be it known that I, JOHN STANLEY RICH- MOND, a subject of His BritannicMajesty King Edward VII, residing at New York, in the borough ofManhattan and State of New York, have invented certain new and usefulImprovements Relating to the Transmission of Electrical Impulses; and Ido hereby declare the following to be a full, clear, and exactdescription of the same, reference being had to theaccompanyingdrawings, forming a part of this specification, and to the letters ofreference marked thereon.

This application is a division of my prior application, Serial No.57,821, filed April 27, 1901, and the invention relates to the artoftransmitting electrical impulses through electrical transmissionmediums, and more especially such impulses as are utilized in the artsof telegraphy and telephony, although not restricted to these arts, theobjects of the invention being toenable such impulses to be transmittedthrough long cables, submarine or otherwise, and to render theirtransmission through short cables more expeditious and eificacious.

The transmission of electrical impulses,par-

ticularly in telegraphy and telephony, has

hitherto been eiiected by what I term single transmissiona. a, thetransmission of electrical impulses produced telephonically,

telegraphically, or otherwise with one generating device through onecircuit, (metallic or otherwise,)in which case capacity has proven to behighly detrimental, especially where a cable or cables form a portion orportions of the working circuit or circuits. To prevent detrimentalinductive eiiects, certain conditions must be established in thecablethat is to say, the sheath of the cable'being zero potential or thepotential of the earth the impulses in the conductor or conductors mustat contiguous points be in potential equally above and equally below thezero potential or potential of the sheath. Obviously the desired endcannot be attained with a singlewire earth-return nor with a metalliccircuit unless the impulses in the two conductors at contiguous pointsbe in potential equally above and equally below thapotential of thesheath,

(No model.) I

and this can only be attained by a system in which the two conductors ofa metallic circuit have an equal capacity inregard to the sheath,

and when the meeting-points of the two halves of the system, one ofwhich includes one conduetor and the other the other conductor, are

maintained at the zero potential, which points respectively above andbelow a potential intermediate to the potential in the conductorsthemselves, yet that intermediate potential may not correspond to thezero potential, and if not the aforesaid detrimental efiiects willoccur. i o

In carrying out the present invention I employ what I term a doubletransmission that is, the transmission through two contiguoustransmission mediums of equal impulses simultaneously varied in equalratio, the in pulses at contiguous points in the two transmissionmediums being simultaneously equal in potential measured frornthe zeropotentia l,but

'difl'ering in this, that the potential of the one is above and that thepotential of the other is below such zero'potential, whereby nodetrimental capacity efiects are produced in so faras the im ulses beingtransmitted are concerned. 11 other words, in accordancewith myinvention the cable, considered as a condenser within asheath or shield,has its contiguous points when in operation in an ideal condition from acharged-condenser point of view, which condition cannot result in anydetrimental so-called capacity efiect, which detrimental so-calledcapacity efiect is but the attempt of a cable-condenser to attain suchideal condition, which ideal condition cannot be established ormaintained by transmission as heretofore practiced. p U

In the practical application of the invention two contiguous conductorsare employed forming the transmitting media of the line, such conductorsbeing as nearly as practicable similar in all respects, especially as totheir resistance and their capacit'y lconsidered as a condenser, themedial points where such transmitting media meetto form the circuitbeing maintained at the potential of the medium contiguous to, butinsulated from, the conductors, such as the cable-sheath, by an earthconnection, and in connection with such conductors there are providedmeans for transmitting through said conductors impulses simultaneouslyequal at contiguous points in the conductors, but of opposite potentialwith respect to the zero potential or potential of the mediumsurrounding, but insulated from, the conductors, and means for makingthe impulses manifest at the receiving-station.

In the drawings illustrative of the invention Figures 1, 2, 3, 4, 5, 6,and 7 are diagrammatic illustrations of the application of the presentinvention to an impulse-transmitting system or systems. Fig. 8represents a crosssection at a point in a cable when the impulses in theconductors at such a point are respectively 50- and 50+.

In said drawings the cable portion of the system is indicated by theletter A, while two conductors in the cable, forming portions of a pairof transmitting mediums, are indicated by the letters Band C, suchconductors being equal and so arranged in the cable as to have from acondenser point of view equal capacities under equally-influencingconditions that is, arranged in the same relation to the sheath a of thecable as shown in Fig. 8-in other words, having their points of similarproximity to the sheath equal, &c. Cables having two or more pairs ofwires should have the core constructed similar to those diagrammaticallyillustrated on page 466 of a work entitled A ilflmual 0f Telephony, byPreece and Stubbs, edition of 1898. The cable A extends between the twostations, and, as shown, the transmitting-stations are indicated by theletter D and receiving-stations by the letter E; but while the drawingsshow a transmitting-station at one end and a receivingstation at theother end it will be understood that each station may be both atransmitting and areceiving station. The conductors B and C are asnearly as practicable of the same resistance and as equal as possible inall respects. They form, respectively, portions of the two transmittingmediums, which mediums when joined together ateach end form a workingcircuit, and any instrument introduced into or influencing onetransmission medium has its counterpartin the other transmission medium,the object being to have both transmission mediums, considered from themedial points or points where the two transmission mediums meet, in allrespects equal to each other. With this object in view the receivinginstrument or instrumentality for making the impulses manifest or theimpulse-creating instrumentality may be introduced as a bridge betweentwo points, one in each transmission medium, such points beingelectrically equidistant from the meeting-point of the two transmissionmediums, in which case when operative one medial point would be at thecenter of the instrument,

as shown, for instance, by the diagrammatic illustration of thereceiving instrument F, Figs. 1, 2, 4:, and 5.

If so desired, two receiving instruments may be introduced, one on eachside of the medial point, as shown by G Gin Figs. 3 and 6, either orboth of which instruments may be utilized. At the transmitting-stationsimilar conditions are establishedthat is to say, the instrument forcreating the impulses may bridge points electrically equidistant fromthe medial point or an instrument be located on each side of the medialpoint.

The impulses may be created by a primary generator, such as a dynamo, orby an impulse instrumentality in conjunction withcurrentgeneratingmeans. In Figs. 1 and Qequal batteriesH and I, locatedin the respective transmission mediums, are shown, the impulse-creatinginstrumentality in Fig. 1 being transmitting instruments KK, one locatedon each side of the medial point. In Fig. 2 a singletransmittinginstrumentL, bridging points electrically equidistant fromthe medial point, is shown. In Figs. 3 and 6two dynamos M Mare shown,one on each side of the medial point. In Figs. 4 and 5 a single dynamo Nis shown, bridging points electrically equidistant from the medialpoint.

The balanced conditions having been established, then when the circuitis working the tension in one conductor may be said to be l potentialand that in the other potential; but in cable-work to a large extent andin other work to a lesser extent condenser conditions are encountered,and this not only between the conductors, but also between theconductors and the medium surrounding and more or less insulated fromthem. In cablework such surrounding medium insulated from the conductorsis the sheath. The potential of such sheath must therefore be taken intoaccount, and to prevent detrimental condenser effects the potential inthe respective conductors must at every contiguous point besimultaneously as equally above (I) in the one as that in the other isbelow the zero (01: or 0) potential of the sheath of the cable. Asillustrated, this is accomplished through establishing an unvarying zero(0i) potential at the medial points in the system, as by a ground orearth connection, which may be the connection P from the medial point atthe transmitting-station, as in Figs. 1 and 3, or the connection Q fromthe medial point of the receiving-station, as in Fig. .6. The desiredresult may be accomplished by a ground or earth connecting the middlepoint electrically, of a resistance bridging points electricallyequidistant from the medial point when in operation, especially wherethe transmitting instrument is located at the medial point, suchresistance acting as a shunt and so arranged that sufiicient so-calledelectricity shall operate in the transmitting instrument or thereceiving instrument if the earth or ground connection is located at thereceiving-station. Figs. 2, 4, and5 illustrate such an arrangement. InFigs. 2 and 5 each earth connection is made to the middle point of theresistance R, which resistance R bridges points'electrically equidistantfrom the medial point situated in the transmitting instrument.

Fig. 7 is a diagrammatic illustration ofthe application of the inventionto a common battery telephonic system showing two subscribers. T T aresubscribers sets, B O and B C being two conductors passing through thecables A A. B and Bare connected, through a retardation-coil Y, to abattery H. C and C are connected, through a retardation-coil Y, to abattery H equal to H. The remaining terminals of H and H are connectedtogether and such connection connected to earth.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-- 1. The hereinbefore described improvementin the art of electrical transmission which consists in producing inadjacent conductors electrical impulses simultaneously equal atcontiguous points but differing in this that the potential of the one isabove and that of.

the other equally below the maintained zero potential; substantially asand for the purposes set forth.

2. The described improvement in the art of electrical transmission whichconsists in the transmission through contiguous conductors capable,under sim lar electrical conditlons, of

similar capacity eifects, of electrical impulses simultaneously equal atcontiguous points and simultaneously varied in equal ratio as-regardsthe two conductors, but difiering in this: that, simultaneously and atcontiguous points, the potential established in one of the conductors isabove while that in the other is equally below the potential of themedium surrounding the conductors; substantially as described.

3. The hereinbefore described improvement in the art of electricaltransmission which consists in maintaining zero potential at themeeting-point of adjacent conductors, and simult'aneously producing insaid conductors electrical impulses simultaneously equal at contiguouspoints but differing in this that the potential in the one conductor isabove andthat in the other equally below the maintained zero potential;substantially as described.

4. The described improvement in the art of electrical transmission whichconsists in'the transmission through contiguous conductors forming partsof a single circuit, of impulses inaugurated by transmittinginstrumentalities common to the two transmission mediums, said impulsesdiffering in this that, simultaneously and at contiguous points, thepotential established in one of the conductors is above while that inthe other is equally below maintained zero potential; substantially asdescribed.

JOHN STANLEY RICHMOND.

Witnesses:

S. W. HUFF, B. M. FLoURNEY.

